The current management of life-threatening hypoxemia/hypercarbia in severe acute respiratory failure (ARF) is suboptimal. Arteriovenous carbon dioxide removal (AVCO2R) in combination with mild ventilation for introduction of oxygen has shown promise. AVCO2R is a mild pumpless technique using existing low pressure drop membrane oxygenators which is less labor intensive, less costly, less complex, and less stressful to the patient. While AVCO2R has shown promise for short duration, ARF therapy requires systems that can operate continuously for weeks. The long-term objective of this program is to develop a long-term AVCO2R system. In Phase I of this program existing AVCO2R membrane oxygenators will be modified to enhance long-term capability from a few hours to in excess of two weeks. Phase I activity will include demonstration that these techniques will maintain initial performance while improving long-term performance and enhancing biocompatibility. Phase II will optimize performance, perform detailed biocompatibility tests, and carry out animal studies. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE